Cocaine abuse in methadone maintenance programs is a major problem for which there is currently no effective treatment. A number of clinical reports and uncontrolled studies have suggested that auricular acupuncture may be efficacious for the treatment of cocaine addiction in opiate- and non-opiate-dependent populations. However, there is no evidence from controlled studies substantiating these claims of efficacy. The proposed study is an eight-week randomized clinical trial of auricular acupuncture for the treatment of cocaine dependence in methadone-maintained patients. The specific aims of the study are fourfold: (a) to determine the effectiveness of auricular acupuncture for the treatment of cocaine dependence in this patient population; (b) to determine if abstinence initiated during treatment is maintained at three- and six-month follow- up; (c) to investigate sex differences in response to treatment; and (d) to explore key predictors of treatment outcome. Two hundred and twenty-two cocaine-dependent, methadone-maintained patients will be stratified by sex and randomly assigned to receive acupuncture in regions used to treat cocaine addiction, or one of two control groups: needle insertion subcutaneously in the ear helix, or relaxation training. All treatment protocols are based on preliminary studies conducted by -our research group. Subjects in each group will receive treatment daily, five times per week, for the first six weeks of the study, and three times weekly for the last two weeks. Cocaine use, verified by urine toxicology screens, will be the primary outcome measure. Other outcome measures include: self- reported frequency and amount of cocaine use, craving in response to drug cues, depression, anxiety, coping, motivation for change, and composite scores on the Addiction Severity Index. Follow-up data will be collected at three and six months post-treatment.